Where does the desktop host produce "current leakage" causing slight currents in the microphone, earphones, and the chassis shell processed by the chassis manufacturer?

Where does the desktop host produce "current leakage" causing slight currents in the microphone, earphones, and the case shell processed by the case processing plant?

The most suitable way to solve this is to do a good job of grounding.

Part of this current sound is the "leakage current" common to metal electrical appliances, as detailed below. Another part is the crosstalk of the power supply circuit, and the poor quality of the switching power supply of the PC host itself, and the noise caused by large ripples.

The cause of "current leakage" in desktop computers is easy to explain. In fact, all AC appliances with metal shells have this problem.

The internal circuit and the shell of an AC appliance are normally insulated, but even so, there can be a potential difference between the metal shell and the internal circuit, and there is an insulation in the middle, which is equivalent to a capacitor. This is a type of distributed capacitance.

Alternating current can pass through capacitors, and the higher the frequency, the more obvious it is. Therefore, in order to ensure safety and equipment stability, all metal-clad AC electrical appliances must have their outer protective wire grounded.

Is there grounding? In addition to shaking the meter, there is a simple way. Use a universal meter, switch to the AC file, two test leads, one end is inserted into the computer shell, or it can be inserted into the motherboard IO baffle, and the other end is hand-held Hold, the human body is equal to the ground at this time. If the meter shows a voltage of tens to tens of volts, it means that your computer is not effectively grounded.

New buildings all have equipotential grounding points. If you are at home, you can open the switchboard to see if there are yellow-green ground wires inside. The constant potential grounding point can be seen in the corridor, a beige sign with an equipotential grounding point printed on it.

As for the grounding resistance, the actual construction is carried out according to the standard of less than one ohm.

If you don’t have one at home, don’t mess around with it. For example, you can find water pipes, natural gas pipes, etc., you can ask the Electricity Bureau to coordinate, or you can find an electrician to do it yourself. Ten yuan a piece, buy a special yellow and green special color wire for the ground wire. After connecting it, use a shaker to measure the ground resistance. You can pour some salt water on the angle iron.